Apparatus for testing cigarettes and the like



June 4, 1968 Q MENGE; ETAL. v 3,386,281

APPARATUS FOR TESTING CIGARETTES AND THE LIKE Filed Jan. l2. 1966;"

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24a l 642 A 336 3240 L/IL J 38 [3:4 w J 396] 3W 3 F", 6406 520 04614 6 101e 1002 1022 H g 2 @61634 630]@21602 1014@ 101611030 /1012 N 163 584m \\\1-\wm\m 1612 '1006J004R n 0 1042 'afl fw f 60s 1000 x um@ 628 G 1034 F H j mlm \\Rq/ l v1020 10m 102s 1010 1040 1030 United States Patent 3,386,281 APPARATUS FOR TESTING CIGARETTES AND THE LIKE Guenter Menge, Sander Damm 13, Hamburg-Lohbrugge, Germany, and Gerhard Koop, Allermoeher Deich 35, Hamhurg-Allermohe, Germany Filed Jan. 12, 1966, Ser. No. 520,221 Claims priority, application Germany, Jan. 23, 1965, H 54,959 7 Claims. (Cl. 73-41) ABSTRACT F THE DISCLOSURE Cigarettes are tested during travel with a conveyor which carries pairs of Iregistering sealing devices having openings for the ends of wrappers on cigarettes. Each sealing device comprises an annular sealing element consisting of elastomeric material and deformable from a first condition in which it can freely receive the end of a cigarette to a second condition in which it forms a uidtight seal around the wrapper in the region adjacent to the respective end. The sealing elements can be deformed mechanically or by means of a uid.

The present invention relates to an apparatus for testing cigarettes, cigars, lter rods and similar articles wherein an open-ended tubular wrapper surrounds a rod-shaped air-permeable filler consisting of tobacco and/ or lter material. More particularly, the invention relates to improvements in the constr-uction, mounting and operation of sealing devices whichmay be utilized in pneumatic testing apparatus to restrict the ow of air or another gas in the course of the actual testing operation. Still more particularly, the invention relates to the construction and operation of sealing devices which are mounted on a conveyor and which travel with the articles during testing.

cit is well known that the condition of cigarettes and analogous articles may be tested by streams of air which are conveyed axially through the articles and whose pressure is thereupon compared with a predetermined pressure. If the actual pressure is less than or exceeds such predetermined pressure, the article is defective and should be disposed of before it can reach the consumer. Streams of air may be utilized to test the condition of the wrapper as well as to determine the density of the filler. In many presently utilized testing apparatus, the articles are examined while traveling sideways on the periphery of a revolving drum. The sealing devices .are disposed at both axial ends of the drum and move toward the respective ends of the articles. As a rule, such conventional testing devices resemble short open-ended cylinders which are fitted over the end of the wrappers. In some instances, the bore of the sealing device tapers outwardly toward its open end, and the smallest diameter of the bore is somewhat smaller than the diameter of the article to be tested so that the end of the article is wedged into the sealing device and its wrapper undergoes at least some deformation. A serious drawback of all such known sealing devices is that they cannot prevent leakage of testing air if the end of the filler is defective, a phenomenon which is observable in connection with cigac ICC rettes where some shredded tobacco is likely to fall out at the ends during travel toward the actual testing station. Even small changes in the density of filler ends can result in leakage of air and can adversely affect the testing operation. On the other hand, and if the sealing devices are too tight, the wrapper and/or the ller will undergo permanent deformation which is equally undesirable.

Accordingly, it is an important object of the present invention to provide a testing apparatus for cigarettes or the like with novel sealing devices which can invariably prevent uncontrolled leakage of testing air and which are constructed, mounted and assembled in such a way that eventual variations in the compactness of the ller ends cannot have an adverse effect upon the testing operation.

Another object of the invention is to provide a pneumatic testing apparatus wherein the sealing devices are constructed in such a Way that they can follow the outlines of wrappers on cigarettes, cigars or filters rather than vice versa.

A further object of the invention is to provide a novel scaling device whose sealing action may be regulated and selected with a desired degree of precision to avoid permanent deformation of tested articles.

An additional object of the invention is to provide a sealing device which may be utilized in presently known testing apparatus.

A concomitant object of the invention is to provide a sealing device which is constructed, assembled and operated in such a way that it cannot cause fallout of tobacco or filter material at the ends of teste-d articles.

Still another Object of the invention is to provide a sealing device which can seal a satisfactory article with the same degree of precision as a defective article.

Another object of the invention is to provide a sealing device which can automatically seal a wrapper as soon as the wrapper is properly located wth respect thereto.

A further object of the invention is to provide a mechanically operated and/or fluid-operated sealing device which can be used in connection with testing of diierent types of articles.

Briefly stated, one feature of our present invention resides in the provision of an apparatus for pneumatically testing cigarettes or cigars with or without lters, filter rods and analogous articles wherein an open-ended tubular wrapper surrounds a rod-shaped iller of air-permeable material. The apparatus comprises a plurality of retaining devices which are mounted on a drum or another suitable conveyor to hold the articles in such a way that the articles move sideways, and a plurality of novel conveyor-mounted sealing devices, at least one for each retaining device and each adjacent to one end of a wrapper which is held in the respective retaining device. The sealing devices are provided with bores or otherwise congurated openings adapted to accommodate the ends of wrappers when the sealing devices are moved toward the associated retaining devices or vice versa, and each sealing device comprises a deformable annular sealing elenient which surrounds at least a portion of the respective opening. The apparatus further comprises deforming means for changing the internal diameters of sealing elements so that, when the end of a wrapper extends into the opening of an adjoining sealing device and the internal diameter of the respective sealing element is reduced, the latter forms a tluidtight annular seal around the wrapper.

Each sealing element may consist of elastomeric material and the deforming :means may comprise a suitable source of compressed gas and/ or a suction generating unit. In such apparatus, the deforming means preferably subjects the sealing elements to radial deforming stresses to reduce the internal `diameters of such sealing elements if the internal dia-meters normally exceed the diameters of wrappers or to increase the internal diameters if the sealing elements normally tend to contract so that they automatically seal the wrappers. It is also possible to subject the sealing elements to axially or radially oriented mechanical stresses, for example, by confining each sealing element in such a way that axial compression brings about automatic reduction of the internal diameter.

The novel features which are considered as characteristie of the invention and set forth in particular in the appended claims. The improved testing apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a fragmentary axial section through a testing apparatus which ern-bodies one form of our invention and wherein the sealing elements comprise elastic sleeve-like diaphragms which are deformable by compressed air;

FIG. 2 is an enlarged view of a portion of the structure shown in FIG. 1 and illustrates one of the sealing devices in idle position;

FIG. 3 is an axial section through a modified sealing device;

FIG. 4 shows the sealing device of FIG. 3 with the sealing element in deformed condition;

FIG. 5 is an axial section through a third sealing device whose sealing element is deformable by suction;

FIG. 6 is an axial section through a sealing device which constitutes a modification of the device shown in FIG. 5;

FIG. 7 is a fragmentary end elevational view of a testing apparatus which may utilize sealing devices of the type shown in FIGS. 5 or 6;

FIG. 8 is a fragmentary axial section through a testing apparatus wherein the sealing elements are defor-mable in response to transmission of mechanical stresses; and

FIG. 9 is an axial section through a further sealing device which is similar to the sealing device of the apparatus shown in FIG. 8.

Referring first to FIG. l, there is shown a portion of a pneumatic testing apparatus for filter cigarettes of double unit length. Each cigarette comprises two cigarette rods of unit length and a filter mouthpiece of double unit length located between the cigarette rods. The means for connecting in the mouthpiece with the cigarette rods comprises a patch of adhesive-coated material which is convoluted around the mouthpiece and around the adjoining ends of the cigarette rods in a manner well known from the art of filter cigarette machines. Reference may be had, for example, to copending application Ser. No. 153,926 of Willy Rudszinat which is assigned to the same assignee. Once the cigarette rods are assembled with the mouthpiece, they form therewith an article G wherein a tubular wrapper, whose ends are open, surrounds a rod-shaped filler which is permeable to air and maybe tested by passing therethrough a stream of air or .another gas and by measuring the pressure of air which issues from the filler. If the wrapper is defective, some air will escape through the leak or leaks and the measurement will indicate that the article is defective. The situation is analogous when the ller is too dense or too loose. The measurement may be carried out in such a way that detection of a leak or another defect automatically results in the generation of ra signal which is utilized -to eject, to destroy or to otherwise dispose of the defective article before it can reach the consumer.

During testing, the articles G are advanced by a testing conveyor (here shown as a drum 600) which rotates about its axis and advances the articles seriatiim from a receiving station, not shown, past one or more testing stations, and to a transfer station Where the satisfactory articles are transferred onto a further conveyor which advances them to a packing machine, to storage or to another station. The drum 600 is provided with axially parallel peripheral retaining devices E which serve to hold the articles G during testing and each of which comprises a row of four pockets 328, 330, 332, 334. The pockets are provided with radially inwardly extending suction ducts which register with similar suction ducts 336 machined into the periphery of the drum 60G and communicate with a suction channel 338 which extends in the axial direction of the drum 600i. The discharge end of each channey 338 is connected with a suitable suction generating device, for example, with a suction fan 338a which tends to suck air through the ducts 336 whereby the wrappers of articles G adhere to the pockets 328, 330, 332, 334 until and unless the respective channel 338 is disconnected from the fan 338:1. The -drum 600 is further provided with groups of pressure ducts 344, one group for each retaining device E, which are disposed between the pockets 328, 330, 332, 334, i.e., three such ducts 344 .are provided for each retaining device. The inner ends of each group of ducts 344 communicate with one of several axially parallel channels 346 which are machined into the drum 609 and may be connected to an air compressor 3460 or an analogous source of compressed gas to effect ejection of defective articles from the respective retaining device or devices. As a rule, the flow of air in the channels 338, 346 is controlled in such a way that the ducts 336 leading from a given retaining device E are disconnected from the fan 338a when the corresponding ducts 344 are connected with the compressor 346a and vice versa so that an article G is not retained by suction when it is to be ejected by blasts of compressed air and that the blasts of compressed air cannot interfere with retention of satisfactory articles or with retention of articles during testing.

The exact construction of the valve system which controls the How of air in the channels 338, 346 is disclosed in the copending application Ser. No. 153,926 of Willy Rudszinat which is assigned to the same assignee. It sufiices to say here that the wrappers of articles G which rest in the retaining devices E in the course of a testing operation are drawn by suction and thus resist the action of centrifugal force when the drum 600 rotates. On the other hand, and when the testing operation is completed and the test results in detection of a defective article, the channel 338 for the respective group of suction ducts 336 is sealed off from the fan 338a so that the defective article may be ejected from its retaining device E, either by gravity and/or by jets of compressed air issuing from the corresponding group of ducts 344.

At each of its axial ends, the drum 600' carries an annular support or holder 636 which serves to accommodate a group of sealing devices H. Each sealing device registers with one of the retaining devices E, i.e., each row of pockets 328, 330, 332, 334 is disposed between two axially spaced sealing devices H. Each sealing device comprises a housing 684 which is reciprocable in the respective support or holder 636 so that it can move toward or away from the adjoining pocket 328 or 334. The maximum distance between a pair of aligned housings 684 exceeds, and the minimum distance between such housings is less than, the length of an article G. Each housing 684 is biased by one or more helical expansion springs 642 (see also FIG. 2.) tending to shift the respective housing 684 axially outwardly and away from the adjoining pocket 328 or 334 so that a roller follower 1638 which is journalled in the housing remains in permanent contact with and tracks the annular face 324a of one of two fixed cams 324 each of which is adjacent to one axial end of the drum 600. The conguration of the cam faces 324a is such that the corresponding sealing devices H are compelled to move toward the respective retaining devices E during a portion of each revolution of the drum 600, i.e., in the course of the actual testing operation. The cams 324 are mounted on a stationary frame F -which supports the drum 600 for rotation about an axis which is parallel with the articles G. The parts 324, 642 together constitute a reciprocating unit which serves to move the sealin-g devices H axially of the drum 600 in automatic response to rotation of the drum. As stated before, the minimal distance between the pairs of registering sealing devices H (i.e., between their housings 684) is less than the axial length of an article G, and the maximum distance exceeds such length.

The external surfaces of the supports 636 slide along stationary distributors or shoes 404, 405, 406, 407 each of which is connected to a suitable air compressor, preferably the same compressor 346er which is connected with the channels 346. That internal surface of each shoe which slides along the periphery of the adjoinin-g support 636 is provided with one or more slits or cutouts which can communicate with annularly arranged rows of ports provided in the supports 636. As shown, each of the shoes 405, 406 is formed with a single slit and such slits communicate with consecutive ports 622 of the respective supports 636 when the drum 600 rotates. On the other hand, the shoes 404, 407 are provided with pairs of slits which respectively communicate with consecutive ports 638, 640 of the corresponding supports 636 when the drum 600 rotates. The nipples 601 of the shoes 404-407 are connected with the compressor 34611 or with another source of compressed gas, and the nipple 601a of the shoe 404 is connected with a testing unit 599 which can measure the pressure of air issuing from one axial end of an article G.

Each housing -684 is formed with a cylindrical compartment 604 (see FIG. 2) Whose open end faces toward the adjoining pocket 328 or 334 and which accommodates a tubular carrier 606 having a pair of radially outwardly extending annular end flanges 608, 610. The carrier 606 surrounds the median portion of an annular sleeve-like sealing element 602 whose end portions extend radially outwardly and are draped around the flanges 608, 610. That portion (614) of the housing 684 which surrounds the compartment 604 defines with the carrier 606 an outer annular chamber 612 which extends between the flanges 608, 610 and communicates with a port 620 machined into the housing 684. The carrier 606 is further formed with at least one but preferably more uniformly distributed radially inwardly extending ports or ducts 616 through which the chamber 612 communicates with an annular chamber 618 dened by the median portion of the sealing element 602 and the internal surface of the carrier. A clamping ring 628 is formed with external threads 626 which mesh with internal threads surrounding the open end of the compartment 604. The purpose of the ring 628 is to press the carrier 606 toward the bottom wall 630 of the compartment 604 so that the radially outwardly extending ends of the sleeve-like sealing element 602 are pressed against the flanges 608, 610 and the chamber 618 is fully sealed at its axial ends, i.e., this chamber can communicate solely with the chamber 612 via ports 616. At the same time, the clamping ring 628 insures that the outer annular chamber 612 can communicate only with the ports 616 and with the port 620 in the housing 684. The centrally located opening 632, of t-he clamping ring 628 is of conical shape and tapers inwardly from both axial ends. This opening 632 registers with the opening of the carrier 606, and it will be noted that the central portion of the sealing element 602 surrounds a substantial part of this composite opening. The minimum diameter of the opening 632 in the clamping ring 628 exceeds slightly the diameter of an article G so that the latter may be conveniently introduced through the opening 632 and through the sealing element 602, preferably all the way to the bottom wall 630 in the housing 684. When the sealing element `602. is not deformed by compressed air, its internal diameter equals or exceeds the minimum diameter of the opening 632 so that the end portion of the article G can be readily introduced into the interior of the carrier 606.

The bottom wall 630 is provided with a bore 634 which extends radially outwardly toward the internal surface of the support 636 and may register with the port 638 or 640 of the shoe 404 or 407 when the housing 684 is respectively moved toward and away from the pocket 328 or 334. The port 620 may register with the port 622 whereby the chambers 612 and 618 receive compressed air (see the arrows 624 in FIG. l) and the internal diameter of the sealing element 602 decreases sufficiently to insure that such element forms a liuidtight seal around the respective end of the wrapper. The bore 634 serves to convey a stream of air to or from the respective end of the article G whereby such stream hows through the filler and may be examined with a view to determine the condition of the wrapper and/or ller by measuring its pressure after it issues from the respective article. The sealing element 602 resembles a diaphragm which always tends to expand radially outwardly to increase its internal diameter and which contracts radially inwardly only when the chamber 618 receives compressed fluid. The pressure of the air stream issuing from an article G is determined by lthe testing unit 599 which produces a suitable impulse, and such impulse is then utilized to seal the respective channel 338 from the fan 338a as well as to connect the respective channel 346 with the compressor 346e to bring about ejection of a defective article. The unit 599 does not produce an impulse when the air stream has passed through a satisfactory article.

The operation of the testing apparatus which is shown in FIGS. l and 2 is as follows:

The drum 600 is driven by a chain or the like, and its retaining devices E receive articles G at a receiving station which is located upstream of the actual testing zone. At the receiving station, the distance between the faces 324a of the fixed cams 324 is rather large so that the distance between the aligned sealing devices H exceeds the axial length of the articles G whereby the articles can be readily introduced'into and properly accommodated in the respective retaining devices E. The channels 338 which travel past the receiving station are connected with the suction fan 338a so that the articles G are immediately held by suction and travel with the respective retaining devices E toward and through the testing Zone. As the articles move away from the receiving station, the cams 324 cause the corresponding pairs of aligned sealing devices H to move axially of the drum 600 and toward' each other so that each end portion of the respective article G enters one of the openings 632 and the interior of the corresponding sealing element 602. As soon as the end portions of the articles to be tested are properly accommodated in the openings of the respective sealing devices, the nipples 601 of the shoes 405, 406 admit compressed air through the ports 622 and 620 (see the arrows 624 in FIG. 1r) whereby such air penetrates into the outer chambers 612, through the radial ducts 616 and into the inner chambers 618 to reduce the internal diameters of the sealing elements 602 and to insure that such sealing elements form lluidtight annular seals around the ends of the respective wrappers. The ports 620 of the housings 684 move into registry with the ports 622 of the supports 636 when the sealing devices H are shifted axially to such an extent that the end portions of the articles G are properly received in the composite openings of such sealing devices. The length of the shoes 405, 406 (as seen in the circumferential direction of the supports 636) is such that the sealing elements 602 remain deformed in the course of the entire testing operation.

Once the sealing elements 602 are properly deformed and seal the respective ends of the wrappers, the corresponding sealing devices reach the slits in the shoes 404, 407 whereby the left-hand nipple 601 of the shoe 407 admits a jet of compressed air which flows through the port 638 of the right-hand support 636 and bore 634 of the right-hand sealing device H to pass through the filler of the respective article G and to thereupon flow through the bore 634 of the sealing device h at the other axial end of the article, through the port 63S of the left-hand support 636, through the right-hand nipple'601a of this lefthand support, and to the testing unit 599 which determines the pressure of the air stream and produces a signal when the pressure differentiates from a predetermined pressure range such as is indicative of a satisfactory article. The aligned sealing device H then advance beyond the shoes 404, 407 and beyond the shoes 405, 406 so that the sealing elements 602 can expand radially outwardly and release the corresponding ends of the wrappers. Also, the followers 1638 of the aligned housings 684 then track outwardly diverging portions of the cam faces 324g so that the springs 642 move the housings 684 away from each other and the clamping rings 628 move axially and away from hte respective ends of tested articles G. The articles are now free to be transferred onto a further conveyor to be thereupon advanced to a packing, storing or other station. When a pair of aligned sealing devices H moves beyond the shoes 40S, 406, the corresponding ports 622 (and for a while also the ports 620) can communicate with the atmosphere so that the air can escape from the chambers v612, 618 and the sealing elements 602 are free to expand radially outwardly.

The manner in which the testing unit 599 can evaluate the streams of air which issue from the nipple 601e may be the same as disclosed, for example, in the copending application Ser. No. 208,189 of Kaeding et al. which is assigned to the same assignee.

Such portions of the shoes 404, 407 which are provided with the outer nipples 601 (nearer to the cams 324) are preferably long enough to admit blasts of compressed air into the ports 640 and thence to the bores 634 when the housings 684 are moved axially and away from each other and subsequent to transfer of tested articles so that blasts of air issuing from the bores 634 can expel and tobacco shreds or particles of dust which might have remained in the respective sealing devices H. The sealing devices are then ready to receive and to seal the ends of the next-following articles which are deposited into the retaining devices E while such retaining devices travel past the aforementioned lreceiving station.

It will be seen that we provide a testing apparatus wherein the sealing devices are constructed, mounted and operated in such a way that their sealing elements 602 can form annular seals around the respective ends of tubular wrappers without subjecting the exposed ends of tobacco llers to axial compression. Also, the ends of the articles need not be forced into the respective sealing elements because the internal diameters of such sealing elements normally exceed the diameters of articles and are reduced only after the ends of articles are surrounded by the sealing devices. Furthermore, and since the sealing elements 602 consist of deformable material, they can readily follow the outline of a wrapper. The pressure of air which is admitted through the shoes 404, 405 is preferably adjustable to make sure that the wrappers are not subjected to excessive deforming stresses by simultaneously insuring that each end of the wrapper on a tested article is properly sealed against uncontrolled entry or escape of air. The shoe 404 may change positions with the shoe 407 so that the streams of testing air will issue at the right-hand ends of the articles G.

FIG. 3 illustrates a modified sealing device K which comprises a housing 734 having a port 720 in communication with an outer annular chamber 712 extending between the end flanges of a tubular carrier 706. This carrier has one or more ducts 716 which connect the chamber 712 with an inner annular chamber 7?;8 shown in FIG. 4. The volume of the chamber 73 is reduced to zero or almost to Zero when the sleeve-like sealing element 702 is allowed to expand radially outwardly in response to innate elasticity of its material. The internal diameter of the sealing element 702 will be reduced so that the latter will form a seal around one end of an article G when the ducts 716 admit air from the chamber 712. In a testing apparatus which utilizes sealing devices K of the type shown in FIGS. 3 and 4, the pressure of air must be higher than in the apparatus of FIG. l, provided that the material of the sealing elements 602 and 702 is the same because the element '702 is under greater initial tension. The diameter of the carrier 706 may be somewhat smaller than the diameter of a carrier 606. The manner in which the sealing device K is mounted on a testing drum is preferably the same as described in connection with FIGS. l and 2.

FIG. 5 shows a sealing device L whose sleeve-like sealing element 002 is deformed in response to evacuation of air from the inner annular chamber 18 which is surrounded by tne carrier 806. The outer annular chamber 812 communicates with a port 020 provided in the housing 884, and this port 020 is connected with a suction fan while the sealing device L travels past the receiving and transfer stations. The median portion of the sealing element 802 tends to reduce its internal diameter so that such diameter is normally less than the diameter of an article G. Therefore, as soon as the end of an article is introduced into the opening of the sealing device L (while the port 820 is connected with the suction fan), the sealing element S02 can immediately form an annular seal around one end of the wrapper when the chamber SIS is allowed to communicate with the atmosphere.

In accordance with a preferred mode of utilizing the sealing device L of FIG. 5, the chamber 818 is evacuated prior to introduction of an article G into the sealing element S02, the chamber 818 then receives a supply of compressed air which assists the innate elasticity of the seal ing element 802 to form a leakproof seal around one end of the wrapper, and the chamber S18 is thereupon again connected with the suction fan to expand the sealing element 802 and to allow for convenient withdrawal of the tested article. By connecting the chamber 818 with a source of compressed air (such as the source 346e shown in FIG. l), we insure that the sealing force exceeds the sealing force which can be generated by the sealing element 302 alone.

The sealing device M of FIG. 6 is analogous to the sealing device L of FIG. 5. The carrier 906 has a front flange 910 (adjacent to the respective retaining device E, not shown in FIG. 6) which extends radially inwardly and imparts to the sealing element 902 the shape of a hollow conical frustum. Thus, the diameter of the sealing element 902 diminishes toward the clamping ring 928 and, when allowed to contract due to its innate elasticity, the element 902 defines an opening whose minimum diameter is less than the diameter of the article G. By evacuating air through the ducts 916, one can reduce the volume of the chamber 918 so that the end of the article G may be introduced into the thus expanded sealing element 902. When the sealing element 902 begins to contract, it engages the wrapper at a point which is spaced from the adjoining end of the article G. This reduces the likelihood of expelling some tobacco shreds in response to sealing engagement between the element 902 and the wrapper of the article G. The sealing action of the element 902 may be enhanced by admitting compressed air through the port 920, chamber 912, ducts 916 and into the chamber 918. It is clear that the flange 600 of the carrier 606 shown in FIG. 2 may extend radially inwardly and radially outwardly to impart to the sealing element 602 a frustoconical shape. The same holds true for the carrier 706 of FIGS. 3 and 4.

Referring to FIG. 7, there is shown a portion of a testing apparatus which comprises a rotary drum-shaped testing conveyor 900 carrying at its axial ends two annular supports or holders 936 for two annularly arranged groups of sealing devices M of the type shown in FIG. 6. The drum 900 rotates in a clockwise direction as indicated by an arrow 950, and one of its supports 936 slides along a stationary distributor or shoe 946 which is connected with a supply conduit 948 leading to an air compressor. The shoe 946 can admit compressed air into the bores 934 (see FIG. 6) of consecutive sealing devices M at one axial end of the drum 900. The air fiows through the articles G and into the corresponding sealing devices M in the other support 936.

The shoe 946 is disposed between two additional distributors or shoes 938, 940 which are connected with suction conduits 942 merging into a common suction line 944 connected to a fan or the like, not shown. The shoe 938 co-nnects the ports 920 of consecutive sealing devices M with the suction line 944 so that the corresponding sealing elements 902 expand and permit the sealing devices to receive the respective ends of the articles G. The shoe 938 is located at or slightly downstream of the aforementioned receiving station where the retaining devices of the drum 900 receive articles which are about to be tested while advancing past the shoe 946. The shoe 940 is located downstream of the shoe 946 and serves to effect renewed expansion of sealing elements 902 so that the sealing devices M may be moved axially and away from the respective ends of tested articles. The shoe 940 is located at or upstream of the aforementioned transfer station Where the tested articles are transferred onto a further conveyor. For the sake of completeness of illustration, the positions of the receiving and transfer stations are respectively indicated by boxes R and T. It is further clear that each of the shoes 938, 940 comprises two sections or units each of which is adjacent to one of the supports 936.

In la testing rapparatus which utilizes sealing devices of the type shown in FIGS. 2 or 3, the shoes 938, 940 are not needed `and are replaced by a shoe which is placed adjacent to the shoe 946- of FIG. 7 to extend upstream and downstream of the shoe 946 and to `admit compressed air to consecutive sealing devices H or K and to thus reduce the internal diameters of the sealing elements 602 or 702. Of course, the apparatus of FIG. 7 may also comprise a further shoe 9:16a which extends between the shoes 93S, 940 and admits compressed air to the chambers 918 in order to -assist the innate elasticity of sealing ele-ments 902 in forming absolutely leakproof seals.

A feature common to the sealing Idevices H, K, L and M resides in that the sealing elements are deformed in response to the action of radially oriented forces which can be produced by compressed -air or Vby suction. It was found that deformation in response to transmission of radially oriented stresses can be effected with a minimal force because the direction of the force need not be changed, i.e., the desired deformation of the sealing element 602, 702, 802 or 902 takes place in the same direction in which the sealing element is subjected to the action of deforming air currents. Furthermore, such radial stressing of the sealing element by suction or by compressed air can be controlled with requisite precision to make sure that the sealing action is just sufficient wit-hout subjecting the wrappers and/or the .fillers to excessive stresses such as could bring about permanent deformation of the filler and/ or crinkling or the wrapper. As a rule, the extent to which the iiller is deformed is Within the plastic limits of the material of which the filler lconsists to make sure that the iller can expand upon completion of the testing operation and reassumes its original shape. By utilizing air, we can expand or contract the sleeve-like sealing elements 602, 702, 802, 902 without appreciable delay so that the application and/or disconnection of sealing devices requires very little time and does not add .appreciably to the duration of a testing operation. In fact, the expansion or -contraction of sleevelike sealing elements in response to changes in air preslsure is practically instantaneous so that it can be said that the expansion or contraction of sealing elements does not in any way `affect the speed of transportation land the duration .of the testing step. Deformation of sealing elements by air 'also insures that all zones of the sealing elements expand or contract to the same extent .and/or that each zone of a sealing element transmits to the adjoining portion of the wrapper the same pressure and brings about the same sealing action. The draping of axial ends of the sealing elements around the anges of the respective carriers 606, 706, 806 or 906 results in substantial savings in space so that the sealing devices H, K, L and M are of very compact ldesign whereby a large number of such sealing devices can be mounted at each axial end of a relatively small testing drum.

When the articles must be tested in rapid sequence, the internal diameter of the sealing element exceeds only slightly the diameter of the articles at the time the latter is introduced into the opening of the sealing device. This insures that the sealing element can rapidly reduce its internal diameter to form an annular seal around the respective axial end of the wrapper. The structure shown in FIG. 7 is particularly suited Ifor testing at short intervals because air admitted by the shoe 94M can eifect instantaneous sealing action as soon as a sealing element moves past the shoe 938. When it is deformed by suction (while passing along the shoe 938), the intern-al diameter :of the sealing element may equal or exceed only negligibly the diameter of an article. While it is preferred to utilize sealing elements which consist of elastomeric material, a sealing element which is merely flexible can be used in certain types for sealing devices, for example, in the sealing device L of FIG. 5 wherein the evacuation of air from the inner annular chamber 818 can result in such deformation of a non-elastic sealing element S02 that the l-atter can permit convenient insertion .or withdrawal of an article G. When the sealing element consists 4of elastomeric material, it should be kept out of contact with the wrapper while the article is being introduced into or withdrawn lfrom the respective sealing device.

The purpose of the clamping rings 623, 728, i828, 928 is to clamp the ends of the respectivey sealing elements and to guide the ends of articles into the openings of such sealing elements, Le., the clamping rings yalso serve as a means for properly centering the articles for satisfactory engagement with the sealing elements. As a rule, the clamping rings will guide and center the articles in such a way that their ends do not come in actual contact with the sealing elements while the corresponding sealing devices move axially and away from the respective axial ends of the testing drum. It will be noted that the sealing devices H, K, L and M are constructed and assembled with a View to prevent mixing of testing air (bore 6134 in FIG. 2) with air (chamber 61-3 in FIG. 2) which is used to deform the sealing elements.

FIG. 8 illustrates a portion of a further testing apparatus wherein the sealing devices N (only one shown) comprise annular sealing elements 1032 which may be subjected to axially oriented mechanical stresses to reduce their internal diameters and to form annual seals around the ends of wrappers on the articles G. The apparatus comprises a rotary testing drum 1000 whose axial ends are connected with two annular supports or holders 1002 (only one shown), and each support 1002 accommodates an annulus of equidistant sealing devices N. The sealing device N shown in FIG. 8 comprises a housing 1004 which is reciprocable in the axial direction of the drum 1000 and is provided with a roller follower 1006 which tracks the face of a iixed annular cam 1008. The housing 1004 is biased toward the cam 1008 lby a helical spring 1010 which is accommodated in and `bears against an annular tiange 1012 of the support 1002. The housing 1004 is further guided in a mutt 1014 which is secured to the support 1002 and is provided with a port 1016 registering with the port 1018 of the member 1002. The hou-sing 1004 comprises a radially outwardly extending annular frange which abuts against one end of the spring 1010. A bore 1020 in the housing 1004 can move into registry with the port 1016 in response to axial displacement of the sealing device N, namely, when the sealing device is moved to its rightmost position and is supposed to admit a stream of compressed air into the corresponding end of an article G. The right-hand portion 1022 of the housing 1004 constitutes a plunger which is reciprocable in a cylinder 1036 reciprocably received in the flange 1012 of the support 1002. The rightmost end of the plunger 1022 carries an annular ange-like compressing member 1024 which can move into compressive engagement with the sealing element 1032. A second compressing member 1034 which resembles a washer is secured to the right-hand end of the cylinder 1036. The left-hand end of the plunger 1022 is surrounded by an annular recess 1026 which accommodates a series of helical springs 1028 serving to bias the plunger away from the cylinder 1036. The sealing element 1032 consists of strongly elastic material which expands radially in response to axial compression. An annular portion or web of the sealing element 1032 extends into an annular groove 1030 machined into the front face of the plunger 1022 so that the parts 1022, 1032 are connected with each other. The arrangement is such that the cylinder 1036 can participate in a portion of each working stroke of the housing 1004, and the length of reeiprocatory movement of the cylinder 1036 is limited by two annular stops 1040, 1042. The stop 1040 is recessed into the peripheral surface of the cylinder 1036 and may move into abutment with the flange 1012. The stop 1042 is recessed into the internal surface of the cylinder 1036 and may move into abutment with the compressing member 1024 of the plunger 1022. rThe forward ends of the springs 1028 bear against an annular abutment member 1038 which is attached to the inner end of the cylinder 1036.

The stop 1040 is located substantially midway between the axial ends of the cylinder 1036 and serves to arrest the cylinder in its foremost position, i.e., when the opening defined by the sealing element 1032 has properly received the left-hand end of the article G. The Stop 1042 determines the extent to which the plunger 1022 can move with reference to the cylinder 1036 in a direction toward the iixed. cam 1008. The stop 1042 also serves as a means for retracting the cylinder 1036 so that the sealing element 1032 may be moved axially and to the left of the corresponding end of the article G. The compressing member 1024 is movable toward the compressing member 1034 to the extent determined by the configuration of the face on the cam 1008, and the maximum distance between the compressing members 1024i, 1034 is determined by the stop 1042.

When the drum 1000 rotates, the follower 1006 rolls along the face of the cam 1008 whereby the housing 1004 moves with reference to the muff 1014 and support 1002. While moving in a direction to the right, as viewed in FIG. 8, the housing 1004 overcomes the -bias of the spring 1010 and moves its plunger 1022 toward the adjoiningr end of the article G which is already held by the corresponding retaining device, not shown. The plunger 1022 and the cylinder 1036 move as a unit until the stop 1040 engages the flange 1012 of the support 1002. The cylinder 1036 then assumes its foremost (rightmost) position and the end of the article G already extends with at least some clearance into the opening defined by the stiil undeformed sealing element 1032. The configuration of the face on the cam 1008 is such that the housing 1004 continues to move in a direction to the right whereby the plunger 1022 moves with reference to the cylinder 1036 CII and its compressing member 1024 reduces the axial length of the Sealing element 1032 by pressing this sealing element against the compressing member 1034. The internal diameter of the sealing element 1032 decreases and this element forms an annular seal around the wrapper of the article G. During its movement with reference to the cylinder 1036, the plunger 1022 compresses the springs 1020. The configuration of the face on the cam 1008 is invariably selected in such a way that the deformation of the sealing element 1032 cannot result in any damage to the article G. When the wrapper of the article G is propcrly sealed, the bore 1020 of the housing 1004 registers with the ports 1016, 1018 and the latter admits a stream of air which passes through the ller of the article and is thereupon evaluated to determine the condition of the article.

The cam 1008 then allows the springs 1010 and 1028 to expand whereby the sealing element 1032 expands axially and increases its internal diameter to release the tested article so that the parts 1032, 1034, 1036 may be shafted axially and away from the left-hand end of this article. In the rst step, only the housing 1004 moves to the left, as viewed in FIG. 8, and entrans the plunger 1022 to relieve the sealing element 1032. When the cornpressing member 1024 reaches the stop 1042, the cylinder 1036 begins to share the movement of the housing 1004 and also moves toward the cam 1008. Such axial displacement of the cylinder 1036 results in movement of the sealing device N to the left and beyond the adjoining end of the tested article.

It is clear that the springs 1028 constitute an optional feature of the sealing device N. Thus, if the innate elesticity of the sealing element 1032 suflices to shift the compressing member 1024 into actual abutment with the stop 1042, the springs 1028 may be dispensed with. Also, the sealing element 1032 need not be of circular crosssectional outline because a sealing element of polygonal or oval outline can be used with equal or nearly equal advantage, especially if the ends of articles G are not exactly round. Furthermore, the sealing element 1032 may be made of several layers or portions each having a different elasticity.

The bias of the spring 1010 is weaker than the bias of the springs 1028. Therefore, the cylinder 1036 will move away from the article G only after the sealing element 1032 is free to expand radially and is disengaged from the article. For the same reason, the sealing ele- 1032 will reduce its internal diameter only when the cylinder 1036 is held against further axial movement with reference to the article. Such construction insures that the sealing element wiil contract or expand only when it is held against axial movement with reference to the wrapper and cannot tear or otherwise damage the wrapper material.

Referring nally to FIG. 9, there is shown a sealing device P which utilizes a ring-shaped sealing element 1132 of circular cross-sectional outline. This sealing element is again accommodated between two relatively movable compressing members 1134, 1150, the latter forming part of a plunger 1122 which is supported by the drum 1100. The compressing member 1134 forms part of or is attached to the inner end of a cylinder 1136 which is reciprocable with reference to the drum 1100. The sealing element 1132 is hollow to enhance its deformablity.

The operation of the sealing device P is analogous to that of the sealing device N. The bore of the plunger 1122 admits compressed air which is caused to pass throcgh the filler of the article G when the latter is properly sealed by the element 1132.

An important advantage of sealing devices N and P is that the axial length of their sealing elements 1032, 1132 can be redcced to a minimum. This holds particularly for the sealing element 1132 of FIG. 9 which may be compressed into the form of a at washer when the compressing member 1150 moves toward the compressing member 1134. If the sealing element 1032 or 1132 is connected to both compressing members 1024, 1034 or 1134, 1150, its internal diameter will increase even faster when the corresponding compressing members are caused to move apart. The sealing element 1032 may be provided with a convex internal surface so that, when undergoing axial compression, it moves into progressively increasing surface-to-surfa'ce contact with the wrapper of the article G.

The sealing elements 1032, 1132 may be installed at the foremost ends of th sealing devices N and P so that such sealing devices must move a short distance in order to fully surround the adjoining ends of the articles. This also contributes to a reduction in the time necessary for completing the sealing action prior to testing, and for rapidly disengaging the sealing devices from tested articls. The importance of speedy testing will be readily understood by considering that a modern cigarette machine will turn out up to 2,000 cigarettes per minute.

Of course, the improved sealing device is susceptible of many additional modifications Without departing from the spirit of our invention. For example, the sealing elements 1032, 1132 of the devices N and P could be subjected to axia'l compressive stresses by resorting to hydraulic or pneumatic (rather than mechanical) deforming devices. Inversely, the sealing elements shown in FIGS. l to 6 could be deformed radially by mechanical means, for example, by resorting to multi-section carriers 606 etc. which act not unlike chucks and can expand and contract. Still further, one could deform a sealing element by subjecting it to mechanical and pneumatic axially and/or radially oriented deforming stresses. All such modifications will be readily understood upon perusal of the preceding disclosure without necessitating additional illustrations.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence ofthe following claims.

What is claimed as new and desired to be protected by Letters Patent is:

1. In an apparatus for testing cigarettes and analogous deformable articles wherein an open-ended tubular wraper surrounds a rod-shaped fluid-permeable filler: a a conveyor; a plurality of retaining devices mounted on said conveyor and arranged to hold the articles during testing: a plurality of sealing devices mounted on said conveyor for travel with said retaining devices and each thereof having an opening arranged to receive one end of a Wrapper while the respective article is held by the of said retaining devices, each of said sealing devices comprising a deformable annular sealing element surrounding at least a portion of the respective opening and having a substantially frustoconical portion which comes into direct-sealing engagement with the wrapper; and deforming means for changing the internal diameters of said sealing elements by iirst causing an increase and thereupon a decrease of such internal diameters so that, once said one end of a wrapping enters the opening of a sealing device in the diameter of the corresponding sealing element decreases, the latter forms a iiuidtight seal around the wrapper.

2. A structure as set forth in claim 1, wherein each of said sealing devices further comprises a tubular carrier surrounding the respective sealing element and defining therewith an annular chamber, each of said carriers having at least one duct which communicates with the respective chamber, said deforming means comprising a source of compressed gas and a suction generator and means for temporarily connecting said ducts first with said suction generator, thereupon with said source and again with said suction generator so that said sealing elements are caused to expand radially outwardly prior to and subsequent to contraction in response to admission of compressed gas into the respective chambers.

3. A structure as set forth in claim 1, wherein said deforming means comprises means for subjecting said sealing elements to radially directed deforming stresses and each of said sealing elements comprising an elastic sleeve having radially outwardly extending end portions, each of said sealing devices further comprises a housing defining a compartment, a tubular carrier received in said compartment and surrounding the respective sleeve between said end portions thereof, and a clamping member bearing against one of said end portions and arranged to press the other end portion against said housing so that the end portions of the sleeve are sealingly pressed against said carrier.

4. In an apparatus for testing cigarettes and analogous articles wherein an open-ended tubular wrapper surrounds a rod-shaped huid-permeable filler, a conveyor; a plurality of retaining devices mounted on said conveyor and arranged to hold the article during testing; a plurality of sealing devices mounted on said conveyor and each having an opening arranged to receive one end of a Wrapper while the respective article is held by one of Said retaining devices, each of said sealing devices comprising a deformable annular sealing element surrounding at least a portion of the respective opening and a tubular carrier surrounding the respective sealing element and defining therewith an annular chamber, said carriers cornprising portions arranged to limpart to the respective sealing elements a frustoconical shape so that each sealing element defines an opening which tapers toward the respective retaining device; and deforming means for changing the internal diameters of said sealing elements so that, once said one end of a wrapper enters the opening of a sealing device and the diameter of the corresponding sealing element is reduced, the latter forms a uidtight seal around the wrapper, said deforming means comprising means for subjecting said sealing elements to radially directed deforming stresses.

5. In an apparatus for testing cigarettes and analogous articles wherein an open-ended tubular wrapper surrounds a rod-shaped fluid-permeable filler, a conveyor; a plurality of retaining devices mounted on said conveyor and arranged to hold the articles during testing; a plurality of sealing devices mounted on said conveyor and each having an opening arranged to receive one end of a wrapper while the respective article is held by one of said retaining devices, each of said sealing devices comprising a deformable annular sealing element consisting of elastomeric material and surrounding at least a portion of the respective opening, a pair of compressing members disposed at the opposite axial ends of the respective sealing element, at least one of said compressing members being movable toward and away from the other compressing member, and a cylinder surrounding the respective sealing element and connected With the other compressing member; and deforming means for changing the internal diameters of said sealing elements so that, once said one end of a wrapper enters the opening of a sealing device and the diameter of the corresponding sealing element is reduced, the latter forms a iiuidtight seal around the wrapper, and deforming means including means for subjecting said sealing elements to axially directed deforming stresses to reduce the axial length thereof whereby said sealing elements contracty radially inwardly and move into sealing engagement with the wrappers, said last mentioned means including means for changing the distance between said compressing members by moving said cylinder and said one compressing member with reference to each other.

6. A structure as set forth in claim 5, wherein each of 15 said sealing devices further comprises a housing connected with said one compressing member and reciprocable with respect to said cylinder, and stop means for limiting movements of said cylinder and said housing with reference to each other.

7. A structure as set forth in claim 6, wherein each of said sealing devices further comprises first resilient me-ans for biasing said one compressing member away from said cylinder and said deforming means comprises and said housing for moving the housing away from the corresponding retaining device.

References Cited UNITED STATES PATENTS LOUIS R. PRINCE, Primary Examiner. second resilient means operating between said conveyor l0 DAVID SCHONBERG, Examiner,

I. NOLTON, Assistant Examiner. 

